4 * This driver supports USB CDC WCM Device Management.
6 * Copyright (c) 2007-2009 Oliver Neukum
8 * Some code taken from cdc-acm.c
10 * Released under the GPLv2.
12 * Many thanks to Carl Nordbeck
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/ioctl.h>
17 #include <linux/slab.h>
18 #include <linux/module.h>
19 #include <linux/mutex.h>
20 #include <linux/uaccess.h>
21 #include <linux/bitops.h>
22 #include <linux/poll.h>
23 #include <linux/usb.h>
24 #include <linux/usb/cdc.h>
25 #include <asm/byteorder.h>
26 #include <asm/unaligned.h>
27 #include <linux/usb/cdc-wdm.h>
32 #define DRIVER_VERSION "v0.03"
33 #define DRIVER_AUTHOR "Oliver Neukum"
34 #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management"
36 static const struct usb_device_id wdm_ids[] = {
38 .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS |
39 USB_DEVICE_ID_MATCH_INT_SUBCLASS,
40 .bInterfaceClass = USB_CLASS_COMM,
41 .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM
46 MODULE_DEVICE_TABLE (usb, wdm_ids);
48 #define WDM_MINOR_BASE 176
52 #define WDM_DISCONNECTING 2
55 #define WDM_INT_STALL 5
56 #define WDM_POLL_RUNNING 6
57 #define WDM_RESPONDING 7
58 #define WDM_SUSPENDING 8
59 #define WDM_RESETTING 9
60 #define WDM_OVERFLOW 10
64 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
65 #define WDM_DEFAULT_BUFSIZE 256
67 static DEFINE_MUTEX(wdm_mutex);
68 static DEFINE_SPINLOCK(wdm_device_list_lock);
69 static LIST_HEAD(wdm_device_list);
71 /* --- method tables --- */
74 u8 *inbuf; /* buffer for response */
75 u8 *outbuf; /* buffer for command */
76 u8 *sbuf; /* buffer for status */
77 u8 *ubuf; /* buffer for copy to user space */
82 struct usb_interface *intf;
83 struct usb_ctrlrequest *orq;
84 struct usb_ctrlrequest *irq;
100 wait_queue_head_t wait;
101 struct work_struct rxwork;
106 struct list_head device_list;
107 int (*manage_power)(struct usb_interface *, int);
110 static struct usb_driver wdm_driver;
112 /* return intfdata if we own the interface, else look up intf in the list */
113 static struct wdm_device *wdm_find_device(struct usb_interface *intf)
115 struct wdm_device *desc;
117 spin_lock(&wdm_device_list_lock);
118 list_for_each_entry(desc, &wdm_device_list, device_list)
119 if (desc->intf == intf)
123 spin_unlock(&wdm_device_list_lock);
128 static struct wdm_device *wdm_find_device_by_minor(int minor)
130 struct wdm_device *desc;
132 spin_lock(&wdm_device_list_lock);
133 list_for_each_entry(desc, &wdm_device_list, device_list)
134 if (desc->intf->minor == minor)
138 spin_unlock(&wdm_device_list_lock);
143 /* --- callbacks --- */
144 static void wdm_out_callback(struct urb *urb)
146 struct wdm_device *desc;
148 spin_lock(&desc->iuspin);
149 desc->werr = urb->status;
150 spin_unlock(&desc->iuspin);
153 clear_bit(WDM_IN_USE, &desc->flags);
154 wake_up(&desc->wait);
157 static void wdm_in_callback(struct urb *urb)
159 struct wdm_device *desc = urb->context;
160 int status = urb->status;
161 int length = urb->actual_length;
163 spin_lock(&desc->iuspin);
164 clear_bit(WDM_RESPONDING, &desc->flags);
169 dev_dbg(&desc->intf->dev,
170 "nonzero urb status received: -ENOENT");
173 dev_dbg(&desc->intf->dev,
174 "nonzero urb status received: -ECONNRESET");
177 dev_dbg(&desc->intf->dev,
178 "nonzero urb status received: -ESHUTDOWN");
181 dev_err(&desc->intf->dev,
182 "nonzero urb status received: -EPIPE\n");
185 dev_err(&desc->intf->dev,
186 "Unexpected error %d\n", status);
192 if (length + desc->length > desc->wMaxCommand) {
193 /* The buffer would overflow */
194 set_bit(WDM_OVERFLOW, &desc->flags);
196 /* we may already be in overflow */
197 if (!test_bit(WDM_OVERFLOW, &desc->flags)) {
198 memmove(desc->ubuf + desc->length, desc->inbuf, length);
199 desc->length += length;
200 desc->reslength = length;
204 wake_up(&desc->wait);
206 set_bit(WDM_READ, &desc->flags);
207 spin_unlock(&desc->iuspin);
210 static void wdm_int_callback(struct urb *urb)
214 int status = urb->status;
215 struct wdm_device *desc;
216 struct usb_cdc_notification *dr;
219 dr = (struct usb_cdc_notification *)desc->sbuf;
228 set_bit(WDM_INT_STALL, &desc->flags);
229 dev_err(&desc->intf->dev, "Stall on int endpoint\n");
230 goto sw; /* halt is cleared in work */
232 dev_err(&desc->intf->dev,
233 "nonzero urb status received: %d\n", status);
238 if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
239 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
244 switch (dr->bNotificationType) {
245 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
246 dev_dbg(&desc->intf->dev,
247 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
248 le16_to_cpu(dr->wIndex), le16_to_cpu(dr->wLength));
251 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
253 dev_dbg(&desc->intf->dev,
254 "NOTIFY_NETWORK_CONNECTION %s network",
255 dr->wValue ? "connected to" : "disconnected from");
257 case USB_CDC_NOTIFY_SPEED_CHANGE:
258 dev_dbg(&desc->intf->dev, "SPEED_CHANGE received (len %u)",
262 clear_bit(WDM_POLL_RUNNING, &desc->flags);
263 dev_err(&desc->intf->dev,
264 "unknown notification %d received: index %d len %d\n",
265 dr->bNotificationType,
266 le16_to_cpu(dr->wIndex),
267 le16_to_cpu(dr->wLength));
271 spin_lock(&desc->iuspin);
272 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
273 if (!desc->resp_count++ && !responding
274 && !test_bit(WDM_DISCONNECTING, &desc->flags)
275 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
276 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
277 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
280 spin_unlock(&desc->iuspin);
282 clear_bit(WDM_RESPONDING, &desc->flags);
287 rv = schedule_work(&desc->rxwork);
289 dev_err(&desc->intf->dev,
290 "Cannot schedule work\n");
294 rv = usb_submit_urb(urb, GFP_ATOMIC);
296 dev_err(&desc->intf->dev,
297 "%s - usb_submit_urb failed with result %d\n",
302 static void kill_urbs(struct wdm_device *desc)
304 /* the order here is essential */
305 usb_kill_urb(desc->command);
306 usb_kill_urb(desc->validity);
307 usb_kill_urb(desc->response);
310 static void free_urbs(struct wdm_device *desc)
312 usb_free_urb(desc->validity);
313 usb_free_urb(desc->response);
314 usb_free_urb(desc->command);
317 static void cleanup(struct wdm_device *desc)
328 static ssize_t wdm_write
329 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
332 int rv = -EMSGSIZE, r, we;
333 struct wdm_device *desc = file->private_data;
334 struct usb_ctrlrequest *req;
336 if (count > desc->wMaxCommand)
337 count = desc->wMaxCommand;
339 spin_lock_irq(&desc->iuspin);
342 spin_unlock_irq(&desc->iuspin);
344 return usb_translate_errors(we);
346 buf = kmalloc(count, GFP_KERNEL);
352 r = copy_from_user(buf, buffer, count);
358 /* concurrent writes and disconnect */
359 r = mutex_lock_interruptible(&desc->wlock);
364 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
366 goto out_free_mem_lock;
369 r = usb_autopm_get_interface(desc->intf);
371 rv = usb_translate_errors(r);
372 goto out_free_mem_lock;
375 if (!(file->f_flags & O_NONBLOCK))
376 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
379 if (test_bit(WDM_IN_USE, &desc->flags))
382 if (test_bit(WDM_RESETTING, &desc->flags))
387 goto out_free_mem_pm;
391 usb_fill_control_urb(
393 interface_to_usbdev(desc->intf),
394 /* using common endpoint 0 */
395 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
396 (unsigned char *)req,
403 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
404 USB_RECIP_INTERFACE);
405 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
407 req->wIndex = desc->inum; /* already converted */
408 req->wLength = cpu_to_le16(count);
409 set_bit(WDM_IN_USE, &desc->flags);
412 rv = usb_submit_urb(desc->command, GFP_KERNEL);
415 clear_bit(WDM_IN_USE, &desc->flags);
416 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
417 rv = usb_translate_errors(rv);
418 goto out_free_mem_pm;
420 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
421 le16_to_cpu(req->wIndex));
424 usb_autopm_put_interface(desc->intf);
425 mutex_unlock(&desc->wlock);
427 return rv < 0 ? rv : count;
430 usb_autopm_put_interface(desc->intf);
432 mutex_unlock(&desc->wlock);
439 * clear WDM_READ flag and possibly submit the read urb if resp_count
442 * Called with desc->iuspin locked
444 static int clear_wdm_read_flag(struct wdm_device *desc)
448 clear_bit(WDM_READ, &desc->flags);
450 /* submit read urb only if the device is waiting for it */
451 if (!desc->resp_count || !--desc->resp_count)
454 set_bit(WDM_RESPONDING, &desc->flags);
455 spin_unlock_irq(&desc->iuspin);
456 rv = usb_submit_urb(desc->response, GFP_KERNEL);
457 spin_lock_irq(&desc->iuspin);
459 dev_err(&desc->intf->dev,
460 "usb_submit_urb failed with result %d\n", rv);
462 /* make sure the next notification trigger a submit */
463 clear_bit(WDM_RESPONDING, &desc->flags);
464 desc->resp_count = 0;
470 static ssize_t wdm_read
471 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
475 struct wdm_device *desc = file->private_data;
478 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
482 cntr = ACCESS_ONCE(desc->length);
486 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
490 if (test_bit(WDM_OVERFLOW, &desc->flags)) {
491 clear_bit(WDM_OVERFLOW, &desc->flags);
496 if (file->f_flags & O_NONBLOCK) {
497 if (!test_bit(WDM_READ, &desc->flags)) {
498 rv = cntr ? cntr : -EAGAIN;
503 rv = wait_event_interruptible(desc->wait,
504 test_bit(WDM_READ, &desc->flags));
507 /* may have happened while we slept */
508 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
512 if (test_bit(WDM_RESETTING, &desc->flags)) {
516 usb_mark_last_busy(interface_to_usbdev(desc->intf));
522 spin_lock_irq(&desc->iuspin);
524 if (desc->rerr) { /* read completed, error happened */
525 rv = usb_translate_errors(desc->rerr);
527 spin_unlock_irq(&desc->iuspin);
531 * recheck whether we've lost the race
532 * against the completion handler
534 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
535 spin_unlock_irq(&desc->iuspin);
539 if (!desc->reslength) { /* zero length read */
540 dev_dbg(&desc->intf->dev, "%s: zero length - clearing WDM_READ\n", __func__);
541 rv = clear_wdm_read_flag(desc);
542 spin_unlock_irq(&desc->iuspin);
548 spin_unlock_irq(&desc->iuspin);
553 rv = copy_to_user(buffer, desc->ubuf, cntr);
559 spin_lock_irq(&desc->iuspin);
561 for (i = 0; i < desc->length - cntr; i++)
562 desc->ubuf[i] = desc->ubuf[i + cntr];
564 desc->length -= cntr;
565 /* in case we had outstanding data */
567 clear_wdm_read_flag(desc);
568 spin_unlock_irq(&desc->iuspin);
572 mutex_unlock(&desc->rlock);
576 static int wdm_flush(struct file *file, fl_owner_t id)
578 struct wdm_device *desc = file->private_data;
580 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
582 /* cannot dereference desc->intf if WDM_DISCONNECTING */
583 if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags))
584 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
587 return usb_translate_errors(desc->werr);
590 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
592 struct wdm_device *desc = file->private_data;
594 unsigned int mask = 0;
596 spin_lock_irqsave(&desc->iuspin, flags);
597 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
598 mask = POLLHUP | POLLERR;
599 spin_unlock_irqrestore(&desc->iuspin, flags);
602 if (test_bit(WDM_READ, &desc->flags))
603 mask = POLLIN | POLLRDNORM;
604 if (desc->rerr || desc->werr)
606 if (!test_bit(WDM_IN_USE, &desc->flags))
607 mask |= POLLOUT | POLLWRNORM;
608 spin_unlock_irqrestore(&desc->iuspin, flags);
610 poll_wait(file, &desc->wait, wait);
616 static int wdm_open(struct inode *inode, struct file *file)
618 int minor = iminor(inode);
620 struct usb_interface *intf;
621 struct wdm_device *desc;
623 mutex_lock(&wdm_mutex);
624 desc = wdm_find_device_by_minor(minor);
629 if (test_bit(WDM_DISCONNECTING, &desc->flags))
631 file->private_data = desc;
633 rv = usb_autopm_get_interface(desc->intf);
635 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
639 /* using write lock to protect desc->count */
640 mutex_lock(&desc->wlock);
641 if (!desc->count++) {
644 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
647 dev_err(&desc->intf->dev,
648 "Error submitting int urb - %d\n", rv);
649 rv = usb_translate_errors(rv);
654 mutex_unlock(&desc->wlock);
655 if (desc->count == 1)
656 desc->manage_power(intf, 1);
657 usb_autopm_put_interface(desc->intf);
659 mutex_unlock(&wdm_mutex);
663 static int wdm_release(struct inode *inode, struct file *file)
665 struct wdm_device *desc = file->private_data;
667 mutex_lock(&wdm_mutex);
669 /* using write lock to protect desc->count */
670 mutex_lock(&desc->wlock);
672 mutex_unlock(&desc->wlock);
675 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
676 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
678 spin_lock_irq(&desc->iuspin);
679 desc->resp_count = 0;
680 spin_unlock_irq(&desc->iuspin);
681 desc->manage_power(desc->intf, 0);
683 /* must avoid dev_printk here as desc->intf is invalid */
684 pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__);
688 mutex_unlock(&wdm_mutex);
692 static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
694 struct wdm_device *desc = file->private_data;
698 case IOCTL_WDM_MAX_COMMAND:
699 if (copy_to_user((void __user *)arg, &desc->wMaxCommand, sizeof(desc->wMaxCommand)))
708 static const struct file_operations wdm_fops = {
709 .owner = THIS_MODULE,
714 .release = wdm_release,
716 .unlocked_ioctl = wdm_ioctl,
717 .compat_ioctl = wdm_ioctl,
718 .llseek = noop_llseek,
721 static struct usb_class_driver wdm_class = {
724 .minor_base = WDM_MINOR_BASE,
727 /* --- error handling --- */
728 static void wdm_rxwork(struct work_struct *work)
730 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
735 spin_lock_irqsave(&desc->iuspin, flags);
736 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
737 spin_unlock_irqrestore(&desc->iuspin, flags);
739 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
740 spin_unlock_irqrestore(&desc->iuspin, flags);
742 rv = usb_submit_urb(desc->response, GFP_KERNEL);
743 if (rv < 0 && rv != -EPERM) {
744 spin_lock_irqsave(&desc->iuspin, flags);
745 clear_bit(WDM_RESPONDING, &desc->flags);
746 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
747 schedule_work(&desc->rxwork);
748 spin_unlock_irqrestore(&desc->iuspin, flags);
753 /* --- hotplug --- */
755 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep,
756 u16 bufsize, int (*manage_power)(struct usb_interface *, int))
759 struct wdm_device *desc;
761 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
764 INIT_LIST_HEAD(&desc->device_list);
765 mutex_init(&desc->rlock);
766 mutex_init(&desc->wlock);
767 spin_lock_init(&desc->iuspin);
768 init_waitqueue_head(&desc->wait);
769 desc->wMaxCommand = bufsize;
770 /* this will be expanded and needed in hardware endianness */
771 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
773 INIT_WORK(&desc->rxwork, wdm_rxwork);
776 if (!usb_endpoint_is_int_in(ep))
779 desc->wMaxPacketSize = usb_endpoint_maxp(ep);
781 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
784 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
788 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
792 desc->response = usb_alloc_urb(0, GFP_KERNEL);
796 desc->command = usb_alloc_urb(0, GFP_KERNEL);
800 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
804 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
808 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
814 interface_to_usbdev(intf),
815 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
817 desc->wMaxPacketSize,
823 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
824 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
825 desc->irq->wValue = 0;
826 desc->irq->wIndex = desc->inum; /* already converted */
827 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
829 usb_fill_control_urb(
831 interface_to_usbdev(intf),
832 /* using common endpoint 0 */
833 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
834 (unsigned char *)desc->irq,
841 desc->manage_power = manage_power;
843 spin_lock(&wdm_device_list_lock);
844 list_add(&desc->device_list, &wdm_device_list);
845 spin_unlock(&wdm_device_list_lock);
847 rv = usb_register_dev(intf, &wdm_class);
851 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
855 spin_lock(&wdm_device_list_lock);
856 list_del(&desc->device_list);
857 spin_unlock(&wdm_device_list_lock);
862 static int wdm_manage_power(struct usb_interface *intf, int on)
864 /* need autopm_get/put here to ensure the usbcore sees the new value */
865 int rv = usb_autopm_get_interface(intf);
867 intf->needs_remote_wakeup = on;
869 usb_autopm_put_interface(intf);
873 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
876 struct usb_host_interface *iface;
877 struct usb_endpoint_descriptor *ep;
878 struct usb_cdc_parsed_header hdr;
879 u8 *buffer = intf->altsetting->extra;
880 int buflen = intf->altsetting->extralen;
881 u16 maxcom = WDM_DEFAULT_BUFSIZE;
886 cdc_parse_cdc_header(&hdr, intf, buffer, buflen);
888 if (hdr.usb_cdc_dmm_desc)
889 maxcom = le16_to_cpu(hdr.usb_cdc_dmm_desc->wMaxCommand);
891 iface = intf->cur_altsetting;
892 if (iface->desc.bNumEndpoints != 1)
894 ep = &iface->endpoint[0].desc;
896 rv = wdm_create(intf, ep, maxcom, &wdm_manage_power);
903 * usb_cdc_wdm_register - register a WDM subdriver
904 * @intf: usb interface the subdriver will associate with
905 * @ep: interrupt endpoint to monitor for notifications
906 * @bufsize: maximum message size to support for read/write
908 * Create WDM usb class character device and associate it with intf
909 * without binding, allowing another driver to manage the interface.
911 * The subdriver will manage the given interrupt endpoint exclusively
912 * and will issue control requests referring to the given intf. It
913 * will otherwise avoid interferring, and in particular not do
914 * usb_set_intfdata/usb_get_intfdata on intf.
916 * The return value is a pointer to the subdriver's struct usb_driver.
917 * The registering driver is responsible for calling this subdriver's
918 * disconnect, suspend, resume, pre_reset and post_reset methods from
921 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf,
922 struct usb_endpoint_descriptor *ep,
924 int (*manage_power)(struct usb_interface *, int))
928 rv = wdm_create(intf, ep, bufsize, manage_power);
936 EXPORT_SYMBOL(usb_cdc_wdm_register);
938 static void wdm_disconnect(struct usb_interface *intf)
940 struct wdm_device *desc;
943 usb_deregister_dev(intf, &wdm_class);
944 desc = wdm_find_device(intf);
945 mutex_lock(&wdm_mutex);
947 /* the spinlock makes sure no new urbs are generated in the callbacks */
948 spin_lock_irqsave(&desc->iuspin, flags);
949 set_bit(WDM_DISCONNECTING, &desc->flags);
950 set_bit(WDM_READ, &desc->flags);
951 /* to terminate pending flushes */
952 clear_bit(WDM_IN_USE, &desc->flags);
953 spin_unlock_irqrestore(&desc->iuspin, flags);
954 wake_up_all(&desc->wait);
955 mutex_lock(&desc->rlock);
956 mutex_lock(&desc->wlock);
958 cancel_work_sync(&desc->rxwork);
959 mutex_unlock(&desc->wlock);
960 mutex_unlock(&desc->rlock);
962 /* the desc->intf pointer used as list key is now invalid */
963 spin_lock(&wdm_device_list_lock);
964 list_del(&desc->device_list);
965 spin_unlock(&wdm_device_list_lock);
970 dev_dbg(&intf->dev, "%s: %d open files - postponing cleanup\n", __func__, desc->count);
971 mutex_unlock(&wdm_mutex);
975 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
977 struct wdm_device *desc = wdm_find_device(intf);
980 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
982 /* if this is an autosuspend the caller does the locking */
983 if (!PMSG_IS_AUTO(message)) {
984 mutex_lock(&desc->rlock);
985 mutex_lock(&desc->wlock);
987 spin_lock_irq(&desc->iuspin);
989 if (PMSG_IS_AUTO(message) &&
990 (test_bit(WDM_IN_USE, &desc->flags)
991 || test_bit(WDM_RESPONDING, &desc->flags))) {
992 spin_unlock_irq(&desc->iuspin);
996 set_bit(WDM_SUSPENDING, &desc->flags);
997 spin_unlock_irq(&desc->iuspin);
998 /* callback submits work - order is essential */
1000 cancel_work_sync(&desc->rxwork);
1002 if (!PMSG_IS_AUTO(message)) {
1003 mutex_unlock(&desc->wlock);
1004 mutex_unlock(&desc->rlock);
1011 static int recover_from_urb_loss(struct wdm_device *desc)
1016 rv = usb_submit_urb(desc->validity, GFP_NOIO);
1018 dev_err(&desc->intf->dev,
1019 "Error resume submitting int urb - %d\n", rv);
1025 static int wdm_resume(struct usb_interface *intf)
1027 struct wdm_device *desc = wdm_find_device(intf);
1030 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
1032 clear_bit(WDM_SUSPENDING, &desc->flags);
1033 rv = recover_from_urb_loss(desc);
1039 static int wdm_pre_reset(struct usb_interface *intf)
1041 struct wdm_device *desc = wdm_find_device(intf);
1044 * we notify everybody using poll of
1045 * an exceptional situation
1046 * must be done before recovery lest a spontaneous
1047 * message from the device is lost
1049 spin_lock_irq(&desc->iuspin);
1050 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */
1051 set_bit(WDM_READ, &desc->flags); /* unblock read */
1052 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */
1053 desc->rerr = -EINTR;
1054 spin_unlock_irq(&desc->iuspin);
1055 wake_up_all(&desc->wait);
1056 mutex_lock(&desc->rlock);
1057 mutex_lock(&desc->wlock);
1059 cancel_work_sync(&desc->rxwork);
1063 static int wdm_post_reset(struct usb_interface *intf)
1065 struct wdm_device *desc = wdm_find_device(intf);
1068 clear_bit(WDM_OVERFLOW, &desc->flags);
1069 clear_bit(WDM_RESETTING, &desc->flags);
1070 rv = recover_from_urb_loss(desc);
1071 mutex_unlock(&desc->wlock);
1072 mutex_unlock(&desc->rlock);
1076 static struct usb_driver wdm_driver = {
1079 .disconnect = wdm_disconnect,
1081 .suspend = wdm_suspend,
1082 .resume = wdm_resume,
1083 .reset_resume = wdm_resume,
1085 .pre_reset = wdm_pre_reset,
1086 .post_reset = wdm_post_reset,
1087 .id_table = wdm_ids,
1088 .supports_autosuspend = 1,
1089 .disable_hub_initiated_lpm = 1,
1092 module_usb_driver(wdm_driver);
1094 MODULE_AUTHOR(DRIVER_AUTHOR);
1095 MODULE_DESCRIPTION(DRIVER_DESC);
1096 MODULE_LICENSE("GPL");